基于摄动法的梁桥开裂后模态分析  

Modal Analysis of Cracked Beam Bridge Based on Perturbation Method

作　　者：段勇 郭智刚[2] 

机构地区：[1]武汉恒顺通勘察设计有限公司,湖北武汉430050 [2]上海应用技术学院轨道交通学院,上海市200235

出　　处：《城市道桥与防洪》2014年第6期275-278,23,共4页Urban Roads Bridges & Flood Control

摘　　要：基于摄动法提出一种针对梁桥开裂后的模态分析方法,采用δ公式模拟了梁裂缝。首先给出了摄动项的一般表达式,获得了受损梁的特征值和模态振型的解析式;然后以一受损简支梁为例,计算了裂纹深度和位置对频率变化的影响。计算结果表明:裂纹会引起梁自振频率的变化,但当裂纹位于梁的反弯点处时梁的频率无变化。This paper proposes a method for modal analysis of cracked beam bridge based on perturbation method. Beam cracks are simulated by formula. The paper firstly gives the general expression of perturbation to achieve the characteristic value of the damaged beam and the analytical mode of modal vibration shape,and then calculates the influence of crack depth and position on the frequency change. The calculation result shows that the crack will cause the change of beam natural frequency, but the beam frequency has no change if the crack is located at the inflection point of beam.

关 键 词：梁 摄动法 裂纹 模态分析 

分 类 号：U442[建筑科学—桥梁与隧道工程]